Spherical reconciliation for a continuous-variable quantum key distribution

Information reconciliation is a significant step for a continuous-variable quantum key distribution(CV-QKD) system.We propose a reconciliation method that allows two authorized parties to extract a consistent and secure binary key in a CV-QKD protocol,which is based on Gaussian-modulated coherent states and homodyne detection.This method named spherical reconciliation is based on spherical quantization and non-binary low-density parity-check(LDPC) codes.With the suitable signal-to-noise ratio(SNR) and code rate of non-binary LDPC codes,spherical reconciliation algorithm has a high efficiency and can extend the transmission distance of CV-QKD.